Answer:
9c^2 - 30cd + 25d^2
Step-by-step explanation:
(3c - 5d)^2
= (3c - 5d) (3c - 5d)
= [3c * 3c] + [3c * -5d] + [-5d * 3c] + [-5d * -5d]
= 9c^2 - 30cd + 25d^2
